Rachel’s line of gourmet yogurts is probiotic, enhanced with Omega 3s, kosher...and fashionable. Why didn’t they put the words “probiotic” on the front of the container? They’d sell more to probiotic-hungry Americans! Read our full review of Rachel’s yogurt.

Probiotics Hype—And Getting Past It

First, I will say this:I researched probiotics and probiotic-containing foods for some three to four weeks before I began to write, and I continued my research during the writing process. I read website information (technical as well as consumer-geared) and newspaper articles, contacted professors, consultants, public relations agencies and manufacturers. I encountered more unsubstantiated claims, misinformation and outright lies than I have with any other type of food I’ve ever researched. The biggest single reason for this is that we don’t know enough about the good bacteria (or, for that matter, the pathogens) in our intestinal tract right now, period. We know that some species can be useful in particular ways, but even that knowledge is limited. We don’t know what many of them really do, we don’t understand if one form is preferable over another for delivering probiotics to the intestinal tract in a live state, we have no idea how many probiotics healthy humans need to ingest to keep their beneficial colonies flourishing and we certainly don’t fully grasp their potential.

If even legitimate researchers are not in agreement on so many aspects of probiotics, how is it possible for product manufacturers to make such a vast number of health claims regarding them? I don’t have an answer for that, but if people were not continuing to buy these products, rest assured they would soon stop being on store shelves. People want quick and easy solutions to multi-faceted, complex health problems, and there will always be those willing to take advantage of that. Probiotics are among the newest wave of “natural” remedies, though they’re not the only one.

Before you rush off to spend money on probiotics, consider the fact that USProbiotics.org maintains that people don’t require probiotics to be healthy. No legitimate agency or organization has come up with a recommended daily intake for them, either. Even now, while much more research is being done on these microbes, results of clinical studies are not always conclusive or definitive, and many studies have been small in scope, very limited in duration or conducted on germ-free mice, the results of said studies not always being possible to extrapolate to very non-germ-free humans. Everyone’s system is different, so you’ll experience an individual reaction to any probiotic or combination of them.

Of equal importance to consider are the extremely high concentrations of probiotics in some sources. As we’ve discussed, people throughout the world have been ingesting probiotics via fermented foods for millennia. But these fermented foods didn’t necessarily contain the super-high number of microbes being put into probiotic foods by manufacturers these days, especially in supplements. Ultimate Flora’s Critical Care supplement contains 50 billion live bacteria per capsule, 30 billion Bifidobacteria and 20 billion Lactobacilli. Bio-K Plus, a liquid supplement, discussed below in this section, guarantees 50 billion live, active cultures at time of consumption.

Right now, not enough is known about how well or how poorly most probiotics survive their encounter with the highly acidic environment of the stomach. If most of them are killed off by their passage through the stomach, high initial concentrations of these bacteria may be necessary if they’re to have any effect. But if the majority survive the early stages of digestion, much lower concentrations would be acceptable, perhaps even preferable. While part of the definition of a probiotic includes a general recognition that the particular microbe is not harmful to the human system, it is not known if regular ingestion of megadoses of probiotics might prove unhelpful or even damaging over time. Yet manufacturers of probiotics and devotees of medical self-help practices continue to tout probiotic-containing foods and supplements as cure-alls, whatever the quantity of probiotics they have.

Among individual probiotic-containing foods, kefir has many passionate, if not rabid, fans, who insist that there’s nothing like it. One of these people is Klaus Kaufmann, author of the 1997 booklet Kefir Rediscovered! The Nutritional Benefits of an Ancient Healing Food. Mr. Kaufmann writes:

...Consuming left-turning lactic acid can be problematic. On the polarized light circuit at least, being right-turning is far more right than being left-turning. For the human body, only the right-turning...lactic acid is natural and physiologically correct. Left-turning...lactic acid is a foreign substance for the human organism. It does not contain the necessary enzymes for proper utilization by the body.

The urinary system flushes the majority of left-turning lactic acid out of the system and the liver converts the remainder into carbonic acid and water.

...The Food and Agricultural Organization of the United Nations investigated the question of lactic acid fermentation. This resulted in the recommendation that consumption of left-turning lactic acid be limited in adults to 100 mg per kg of body weight. There is no limitation, however, for right-turning lactic acid for adults. In foods prepared for babies and toddlers, on the other hand, only right-turning lactic acid should be used.

For these reasons, large quantities of yogurt (more than one liter per day) are not good even for adults, as their overwhelming content of left-turning lactic acid can lead to a strain on the metabolism. Consumption of large quantities over extended periods can also harm the flora normally living in the intestines. Homemade, thickened milk on the other hand, contains both kinds of lactic acid, with only a small excess of one kind or the other.

Well, that’s a little worrying, isn’t it? A liter (just over one quart) of yogurt is more than most people consume in a single day, but, like many yogurt fans, I do go through a good amount of it. Maybe we shouldn’t be eating so much yogurt if the left-turning form of lactic acid isn’t recognized by the human system and can potentially be harmful if too much is ingested; who knows what the long-term effects might be? And what about the lactic acid in commercially-produced kefir, as opposed to homemade?

Before you get too frazzled thinking about either issue, understand that there are serious problems with the quoted passage. It’s true that certain chemical compounds have both right- and left-turning forms, and that one form or the other (it isn’t always consistent) can be harmful or beneficial to the human system. However, no one except Mr. Kaufmann appears to be aware that any form of lactic acid has any detrimental effects on anyone (with the exception of infants with short bowel loop syndrome, though this is a rare condition).

I contacted Stonyfield Farm (the yogurt manufacturer); Helios Nutrition, Ltd; Manfred Kroger, Professor Emeritus of Food Science at The Pennsylvania State University; and the Food and Agricultural Organization (FAO) of the United Nations. When I couldn’t find the FAO’s recommendation for left-turning lactic acid consumption on their website, I e-mailed them to ask for a link to the article or paper containing it. They replied that no such information existed anywhere on its website or in other repositories of information. Neither Stonyfield Farm’s R & D people nor anyone at Helios (who you’d think would have a vested interest in such a statement) were familiar with this “data.” Professor Emeritus Kroger, who has worked in the dairy industry for much of his long career, notes that he is not aware of any FAO statement on the consumption of any type of lactic acid from fermented milk products, and that, to his knowledge, “the yogurt- and kefir-makers of the world are not aware of it either.” He adds, “Think of it, people have been consuming fermented milk since Biblical times. In India, consumption of dahi is huge; in Europe, the Finns and the Dutch consume the most cultured dairy products. Shouldn’t we have heard of any problems from those usages by now?”

Mr. Kaufmann’s booklet was sent to me as part of a press kit by the public relations agency for Lifeway Kefir. In a way, it’s understandable, as Lifeway and its founder are mentioned favorably in the booklet. But one has to wonder if the public relations agency has bothered to read the literature they send out. Attempts to search for Mr. Kaufmann have proven fruitless, and it seems that the house which published this booklet has folded.

Lifeway also has the intriguing statement on its website that “due to its unique microbial composition,” it is the “only real kefir” in the United States. The Federal Standard of Identity for cultured milk products in the U.S. (which includes kefir) does not delineate specific microbes that must be included in kefir. And the Codex Alimentarius, created by the FAO and World Health Organization (WHO) of the United Nations and serving as a set of international guidelines and standards for manufacturers and consumers, states only that any kefir shall contain “starter culture from kefir grains, Lactobacillus kefiri, species of the genera Leuconostoc, Lactococcus, and Acetobacter growing in a strong specific relationship,” noting that kefir grains “constitute both lactose fermenting yeasts (Kluyveromyces marxianus) and non-lactose-fermenting yeasts (Saccharomyces unisporus, Saccharomyces cerevisiae, and Saccharomyces exiguous).” The Codex Alimentarius also calls for starter bacteria to be “viable, active and abundant in the product to the date of minimum durability,” unless the product is heat-treated after fermentation. But, again, there is no set roster of probiotics the finished kefir must contain.

In addition, in 2006, Lifeway bought Helios Nutrition, Ltd., a former rival kefir manufacturer, and continues to produce kefir under both the Lifeway and Helios labels, making it even stranger for Lifeway to claim that kefir sold under its name is the only genuine article in this country.

If you believe you can eat yogurt and avoid the spin doctors, think again. Current FDA Standards of Identity for yogurt were last revised in 1982, and there are loopholes in these regulations through which you could drive a truck. Just because it’s called “yogurt,” there’s no guarantee that it contains any beneficial bacteria. In an attempt to distinguish their products from those that don’t contain probiotics, some yogurt manufacturers spell out the cultures they use in their ingredient lists; others merely state that their yogurt is made with “cultured milk.” One trade organization, the National Yogurt Association, has developed the “Live and Active Cultures” (LAC) seal. Yogurts displaying this seal, refrigerated or frozen, must contain a certain level of two cultures (Lactobacillus bulgaricus and Streptococcus thermophilus) per gram of product at the time of manufacture as well as at expiration date. Use of this seal is voluntary, so your yogurt might contain live and active cultures but not carry the seal. Stonyfield Farm, for instance, tells me that its yogurts exceed the NYA “Live and Active Culture” requirements, but the cartons do not display the seal.

If you live in the U.S., you’ve seen advertisements over the past year for Dannon’s Activia, a probiotic yogurt supposed to help ensure regularity. One of the beneficial bacteria included in this product is called Bifidus regularis in the U.S. (this same culture has different names in other nations, such as Bifidobacterium lactis in Canada and Bifidus activo in marketing materials for Spain). In fact, Bifidus regularis, a name that sounds scientific in origin but isn’t, is officially Bifidobacterium animalis DN 173-010. If a scientist or company isolates or breeds a new organism, they also have the naming rights to that organism. And there is no central agency to oversee this process; one organism may be known by multiple names, as is the case here. So Bifidus regularis, it turns out, is merely a proprietary name and marketing gimmick for one of the 30-odd strains of Bifidobacteria currently recognized. The same is true for DanActive (marketed as Actimel in other countries).
The proprietary strain of bacteria here is called Lactobacillus casei immunitas (in the U.S., it’s called L. casei defensis). Has research been done on these proprietary cultures? Yes. Unquestionably, there have been some positive results. Despite this, and the aggressive advertising for both products, there’s no guarantee that either will change your life.

The list of claims and questionable information goes on and on. The liquid supplement Bio-K Plus contains two cultures, Lactobacillus acidophilus and Lactobacillus casei. A section of this product’s website is devoted to frequently asked questions; there, the issue of why this product contains only two strains of friendly bacteria is raised. The answer, supposedly, is that “when too many different bacteria are combined, they can compete against each other and limit the concentration of the most effective strains.” The manufacturer insists that all of its statements are supported by research. However, when asked, they sent me 17 articles on the company and the product. I read all of them. There is no mention anywhere of too many strains of probiotics competing against one another. In fact, a microbiologist I know tells me that different species of probiotics can actually complement each other in their work. Mary Ellen Sanders, quoted above (see Forms of Probiotics Available to Consumers), tells me she "knows of no research that would substantiate" this statement.

The website for Bio-K Plus also declares that, for a probiotic to be effective, it must deliver a minimum of 50 billion bacteria at consumption, with a carrier of “enriched dairy ingredients” to give the bacteria the energy necessary to multiply in the body and protect them through the stomach. But Dr. Sanders disagrees, saying that the figure of 50 billion bacteria is “patently an unsubstantiated over-generalization,” adding that she believes the probiotic “must have the number of live cells that match the dose delivered in the human study that documented the health effects.” For some strains, this might be far more—or fewer—than 50 billion. And she explains that using “enriched dairy ingredients’ as a vehicle for probiotics is not necessary, as noted earlier in this article.

There is one further facet of the numbers game in probiotics. It’s not uncommon to see a product guaranteeing a specific number of beneficial bacteria “at date of manufacture,” but this statistic is meaningless. Why? Because you don’t consume products at the date of manufacture. In the case of a supplement, especially, months can elapse between the date of manufacture and the date you purchase the product—and even then, the supplement will have an expiration date months farther down the line. What you want to know is how many of the beneficial bacteria will be alive by the expiration date of the product. After all, anyone can dump probiotics into a product at the time of manufacture, but if few or none are left alive by the time you consume it, what’s the point?

Is there any way to avoid the fabrications and unsubstantiated claims? You can steer clear of most of them by doing some homework of your own. Since everyone’s system is different and you will react to probiotics like the individual you are, it’s probably not a good idea to have too much faith in the testimonials on websites. Remember, it’s highly unlikely that any probiotic food manufacturer would put any negative comments on its website (as an aside, I recently had a negative experience with one particular probiotic food myself, so I know it can happen. When I contacted the manufacturer, they seemed shocked, and told me no other adverse reactions had been reported, even in people who ate several times the quantity of this product I ingested per day. No sane manufacturer would put my comments on its product’s website, but this is also an example of a highly individualized reaction; I know several people who tell me this same product has helped them greatly).

The most sensible advice I’ve seen comes from USProbiotics.org. This organization urges those interested in a probiotic-containing product (food or supplement) to contact the manufacturer. Ask questions! Ask about health benefits that have been documented for the specific product (including copies of published research articles), concentrations of probiotics present in the product at the end of shelf life, how thoroughly the company oversees its product once it’s left the manufacturing plant and whether the manufacturer uses an independent and objective laboratory to ensure the verification of label claims. Even better, the website urges consumers to pay attention to the effects a probiotic has on your unique system.

Please don’t regard probiotics as a magic bullet for overall good health! As already mentioned, Attune Foods, from Mill Valley, California, has some statements on its website that are overzealous. On the other hand, it is to this company’s credit that the same website, in at least two places, reflects the fact that its probiotic products (or anyone else’s) are not a substitute for a good diet, regular exercise, sufficient sleep, frequent hand washing and the like.
Continue to Part VII:
Conclusions About Probiotics